In the Volsunga Saga, Bikki is the counselor of King Jormunrek. Brynhild prophesies Svanhild's downfall through Bikki's counsels in this chapter of the Saga.
In another chapter, she accuses Randver and Svanhild of being romantically involved and plots their death.
Information taken from The Saga of the Vulsungs, published by Penguin Classics